There exists a problem which with respect to humidifiers that are being used in a hospital or other institutional health locales. The environment there may contain a variety of harmful bacteria that are circulated and re-circulated through humidifiers in which there is open communication between the air in the environment and the water or water vapor used in the system. The most commonly used humidifier systems incorporate a fan to circulate not only vapor but droplets of moisture which are entrapped in the air flow and passed about in the external environment. Systems of this type further have the problem of concentrating moisture in areas or on wall surfaces thus encouraging mold and the growth of additional bacteria in parts of the environment.
Humidifier systems in which evaporation of water vapor and water droplets are made from an open outlet are known in the prior art. One such system is shown in U.S. Pat. No. 2,211,407 issued on Aug. 13, 1940 to H. Christenson for "Portable Vaporizer." That humidifier uses a multiple compartment arrangement but allows an open top of the boiler to emit the vapor thus allowing free intercommunication between the atmospheric environment and the water in the system.
A still further automatically operated humidifier is shown and described in U.S. Pat. No. 1,791,313 issued Feb. 3, 1931 to W. F. Hillpot for "Automatically Operative Humidifier." This system incorporates a number of horizontally arrayed pans and heaters, but once again the vapor being emitted and the water in the system are in communication with the atmosphere during its operation.
An additional system for medicating and vaporizing the atmosphere is shown in U.S. Pat. No. 2,070,378 issued on Feb. 9, 1937 to A. B. Stout for "Medicated Steam Bath." The humidifier system shown in this patent once again has the drawback of having openings and providing free inter-communication between water in the humidifier and the air in the atmosphere.